update s2i docs

Signed-off-by: zhuxiaoyang <sunzhu@yunify.com>

docs/en/concepts-and-designs/README.md

@@ -40,7 +40,7 @@ TODO(@runzexia)
 
 ### KubeSphere S2I/B2I 
 
-TODO(@soulseen)
+Read [S2I/B2I Overview](s2i_b2i_overview.md)
 
 ### KubeSphere Monitoring 
 

docs/en/concepts-and-designs/s2i_b2i_overview.md

@@ -0,0 +1,22 @@
+# Kubesphere S2I/B2I overview
+
+Kubesphere S2I/B2I provides easy CI/CD functionality. 
+
+It will installed in namespaces `kubesphere-devops-system` by enable devops component.
+
+In S2I, all resource and CI/CD steps are defined with [Custom Resource Defintion](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) (CRD). You can operate all s2i resource by call k8s api directly.
+
+There are two mudule included in the S2I component:
+
+1. S2I Operator: A Kubernetes CRD controller that provides easy Kubernetes-style resources for declaring CI/CD-style pipelines
+2. S2IRun: It is the instance that executes the s2i build process in containers.
+
+Besides, the S2I stack includes following CRD resources:
+
+1. s2ibuildertemplates: defines information about S2I builder image.
+2. s2ibuilders: all configuration information used in building are stored in this CRD.
+3. s2iruns: defines an action about build
+
+Also you can install S2I component in any kubernetes cluster without kubesphere.
+
+Want to see more about s2i, please jump to [S2I Operator](https://github.com/kubesphere/s2ioperator) and [S2IRun](https://github.com/kubesphere/s2irun)

docs/en/guides/README.md

@@ -60,7 +60,9 @@ TODO(@runzexia)
 
 ### KubeSphere S2I/B2I developer
 
-TODO(@soulseen)
+1. If users who are interested in S2I/B2I, please read the documentation of [S2I/B2I](https://github.com/kubesphere/s2ioperator#source-to-image-operator) to get start it.
+
+2. For developers who are want to contribute, read the documentation according to the [Development Guide for S2I/B2I](https://github.com/kubesphere/s2ioperator/blob/master/docs/DEVELOPMENT.md)
 
 ### KubeSphere Monitoring developer